A dark-field defect inspecting apparatus is an inspecting apparatus with the aim of observing a high-contrast ultrafine structure and performing a defect inspection by observing scattered light from an observation test sample.
In the semiconductor manufacturing apparatus, efforts have been underway in order to stabilize an apparatus called EES (Equipment Engineering System), reduce a difference in performance among apparatuses, and predict sporadic failure. In EES, it has been sought to achieve the above-mentioned aim by collecting, storing, and processing a large amount of data of a whole process.
In semiconductor manufacturing and magnetic head manufacturing lines, with microfabrication of an inspection subject, a defect signal to be detected becomes weaker. In particular, in a dark-field defect inspecting apparatus, scattered light is used for defect detection, and demands for stably detecting weak light are strong. To stably detect weak light, the apparatus state is desired to be kept constant at a high level.
Japanese Patent Application Laid-Open Publication No. 2007-273513 (Patent Document 1) discloses an automatic calibration technology for a spatial filter mounted in a dark-field inspecting apparatus. In this technology, diffracted light from a periodic pattern on a subject wafer is observed on a pupil, and the spatial filter is automatically set so that the transmission light amount is minimum.
Japanese Patent Application Laid-Open Publication No. 2007-248086 (Patent Document 2) describes an apparatus including a mechanism correcting a change in imaging position of an imaging lens due to changes in temperature and atmospheric pressure in an inspecting apparatus.